Laryngoscope

ABSTRACT

The present invention is a self-retaining laryngoscope composed of a palate brace or blade, a slider, and a tongue blade. The angulated tongue blade puts less force on the blade, reduces trauma, and is not conducive for mechanical failure. The slider interacts with the tongue blade by widening the opening of the mouth, and acts as a bite block. The fenestrated palate blade provides an unobstructed view of the vocal cords during intubation, and allows removal of the laryngoscope over the endotracheal tube without displacing it. The result is a laryngoscope that requires only one hand to use properly, and has superior retraction due to its shape.

CITATION TO PARENT APPLICATION

This is a non-provisional application which claims priority, pursuant to35 U.S.C. 119, to U.S. provisional application Ser. No. 60/828,383,filed 6 Oct. 2006.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to medical instruments, and moreparticularly to an improved laryngoscope.

2. Background Information

The early need to visualize the larynx was for surgical purposes. As amedical student in 1829, Benjamin Guy Babington created a “glottiscope.”One shank held down the tongue while the other was positioned along thepalate. Sunlight provided the illumination for a view of the glottis.The glottiscope was later termed the laryngoscope by his contemporary,Thomas Hodgkins. In 1844, surgeon John Avery developed a head-mountedmirror that reflected candlelight onto a mirror housed within aspeculum. But it was Manual Garcia (1805-1906), a professor of singingat the Royal Academy of Music in London, who is generally credited withthe discovery of laryngoscopy. In 1854, he utilized a dental mirror incombination with a hand-held mirror reflecting sunlight to visualize hisown larynx and trachea during inspiration and vocalization. At the ageof 100, he was honored by the most prominent laryngologists of his timeas the Father of laryngology. A laryngology clinic was established inVienna in 1870 and minor surgical procedures were performed under visualcontrol. British surgeon William Macewen was the first to intubate thelarynx for surgical purposes. He practiced blind, digital intubation oncadavers and eventually employed this technique to perform a compositeresection in 1878. Pediatrician Joseph O'Dwyer worked at New York City'sFoundling Asylum, where he developed instruments to enable trachealintubation that saved the lives of hundreds of children suffocating fromdiphtheria.

Hans Kuhn modified O'Dwyer's instruments and created a long, flexiblemetal endotracheal tube and introducer, but his method still dependedupon blind insertion, as light sources were inadequate to permitprogress in direct laryngoscopy (DL). In 1895, Alfred Kirstein learnedof an inadvertent tracheal insertion of an esophagoscope, and proceededto develop a rigid laryngoscope with transmitted light. This consistedof a lamp within the handle, focused on a lens and redirected throughthe scope by a prism. Chevalier Jackson subsequently modified Kirstein'slaryngoscope by providing distal illumination with a tungsten bulb. In1913, Henry Janeway devised an open-sided laryngoscope withbattery-operated distal illumination specifically for endotrachealintubation.

In 1941, Robert Miller introduced a new, longer, lower profilelaryngoscope, which was designed to pick up the epiglottis. This bladerequired limited mouth opening but also left little space to manipulatethe endotracheal tube (ETT). In 1943, Robert Macintosh described acurved blade to elevate the epiglottis by exerting its force on the baseof the tongue. He believed that reducing contact with the epiglottiswould be less stimulating and provide more room for manipulation of theETT. Although both blades have been variously modified in the interim,they continue to dominate the field of laryngoscopy. Yet they both failto provide an adequate glottic view in a small but significant number ofpatients.

Although there have been advancements in larygoscopy, e.g., fiberoptics, varying techniques, lighted wands, and a number of technologicalmodalities, the basic laryngoscope, which is far and away the mostutilized instrument, has not materially improved since the early 1940s.

After years of clinical studies, it is clear that positioning alone doesnot align the mouth, pharyngeal and laryngeal axes and that force mustbe applied to achieve this. In any situation involving the care of acritically ill or injured person, the first consideration is alwaysestablishment and maintenance of the airway. It is estimated that failedintubation, especially in the emergency and austere environment, is theleading “preventable” cause of morbidity and mortality. In thepre-hospital environment, it is estimated that intubation success ratesvary from approximately 85-95%. This compares to the approximate 99%success rates in hospitals. The main reasons for such a disparity aretraining, experience, resources, and technique.

The inability to see the larynx generally results in multiple orprolonged laryngoscopic attempts with increasing force, and isassociated with esophageal, pharyngeal and dental injury, arterialdesaturation, hemodynamic instability and unplanned intensive care unitadmissions. An American Society of Anesthesiologists Task Force'sdefinition of a difficult laryngoscopy states that “it is not possibleto visualize any part of the vocal cords after multiple attempts” and adifficult tracheal intubation as one which “requires multiple attempts.”Though successfully accomplishing intubation is important, it is notenough. Intubation without an adequate laryngeal view should be regardedas a “near-miss,” which is incentive enough to improve airway managementtechniques and reduce reliance upon luck and multiple or forcefullaryngoscopies.

The laryngoscope of the future will provide predictable laryngealexposure and consistently successful intubation. It will be easy tolearn, quickly performed and will impose less stress upon the patient.It will be inexpensive to acquire and robust enough to withstand thehostile environment of the pre-hospital setting as well as the operatingroom. It will not depend on sunlight for reliable laryngealillumination.

Presently known prior art includes the following:

U.S. Pat. No. 4,570,614, which issued to Bauman on Feb. 18, 1986,teaches a laryngoscope with a single disposable nonmetallic blade, alight source disposed within the handle and a light conductor disposedadjacent to and held by the blade. Typical of the prior art, thisapparatus requires two hands to operate, and perhaps even twocaregivers, if the patient's mouth and head must be stabilized. Lacy(U.S. Pat. No. 5,355,870) and Bar-Or et al. (U.S. Pat. No. 5,702,351)also teach disposable plastic single blades used in combination with alight source in a laryngoscope.

U.S. Pat. No. 4,573,451, which issued to Bauman on Mar. 4, 1986, teachesa laryngoscope blade which has a tip that is capable being bent orflexed in the direction of the handle of the laryngoscope. This allowsthe patient's epiglottis to be lifted to expose the patient's larynx.This is a single blade instrument. It is provided with a ratchet lock tomaintain the bend in the tip. This instrument can bend in only onedirection, to lift the epiglottis. Locking the laryngoscope blade in anoperable position is also shown in U.S. Pat. No. 5,651,760, but thislock/unlock mechanism functions to enable the instrument to be compactwhen it is not in use.

U.S. Pat. No. 5,036,835, which issued to Filli on Aug. 6, 1991, teachesa slideably adjustable spatula portion in the laryngoscope blade. Thefunction of this spatula is to act as a tongue depressor to facilitateinspection of the pharynx and larynx, or the insertion of an anestheticbreathing tube. This apparatus uses a single blade with a sliding part,which does not lock in position.

U.S. Pat. No. 5,070,859, which issued to Waldvogel on Dec. 10, 1991,teaches a laryngoscope that incorporates a dynamometer in order tomeasure the force used by the caregiver to examine the patient. Thisinvention is an attempt to avoid trauma to the patient that can occurusing prior art apparatus.

U.S. Pat. No. 4,517,964, which issued to Upsher on May 21, 1985, teachesa dual bladed laryngoscope, wherein one conventional blade carries itsown light source and the second blade is a light guide for a secondlight source in the handle of the instrument.

U.S. Pat. No. 5,498,231, which issued to Franicevic on Mar. 12, 1996.This apparatus is the current state of the art in the field oflaryngoscopes. Franicevic teaches a reusable laryngoscope for use “indifficult intubation due to malformation of the jaws, tongue, pharynx,larynx or neck as a result of trauma, edema, inflammation or congenialanomalies.” This laryngoscope has a hollow body terminating at itsdistal end in a pair of opposed blades that can be spread apart by thecaregiver. An endotracheal tube slides through the hollow tube in thecenter of the instrument. Light conducting means are provided toilluminate the larynx. The device includes a fiberoptic optical systemfor inspecting the larynx during intubation. Franicevic is animprovement on the “bendable tip” of Bauman, cited above. The singledistal spreading of the “beak” taught by Franicevic allows some liftingof the soft tissue, but it does nothing to open the mouth or depress thetongue. Franicevic teaches a bias spring to keep the distal bladesclosed when they are not positively spread apart by the caregiver. Thisapparatus is not locking or self-retaining in the airway. It also is notdisposable and its complex mechanism makes it difficult to adequatelysterilize.

The closest prior art known to the present inventor is U.S. Pat. No.5,938,591, which issued to Minson, the present invention, on Aug. 17,1999. The '591 patent is a disposable self-retaining laryngoscopes usedfor orally intubating a patient with an endotracheal tube. However, thisdesign ultimately failed in almost every configuration. The currentinvention is not similar to the '591 patent: the tongue blade, thepalate blade and slider have all been changed significantly. Lengths,angles, and the configuration of the invention have all substantiallychanged relative to the '591 patent. For example, the fenestration ofthe improved palate blade allows removal of the laryngoscope over theendotracheal tube without displacing it. This is not possible with the'591 patent.

Despite all of the benefits from the limited improvements of the basiclaryngoscope over the decades and the alternatives thereof, there stillexists the need for an improvement in laryngoscopic technology at themost basic level to address the aforementioned issues. The number ofdifferent variations of laryngoscope found in the prior art is a goodindication that many experts skilled in this art have tried to findsolutions to these problems. Current technology requires thatindividuals “retract” the airway with one hand while attempting tointubate with the other. In fact, four hands may be needed to hold thehead and mouth of the patient, operate the laryngoscope and intubate thepatient. Therefore, an improved laryngoscope is needed thatincorporates 1) hands-free application for simultaneous suction andintubation, which is especially important in trauma, and 2) improved andbroader illumination. Until now, such an invention does not exist.

SUMMARY OF THE INVENTION

In view of the foregoing, it is an object of the present invention toprovide an improved laryngoscope.

It is another object of the present invention to provide an improvedlaryngoscope that exhibits hands-free application.

It is another object of the present invention to provide an improvedlaryngoscope with an improved and broader illumination.

It is another object of the present invention to provide an improvedlaryngoscope with a self-retaining mechanism.

It is another object of the present invention to provide an improvedlaryngoscope consisting in part of clear plastic.

It is another object of the present invention to provide an improvedlaryngoscope to be strong, inexpensive, and simple to use.

It is another object of the present invention to provide an improvedlaryngoscope that facilitates intubation more readily than pre-existinglaryngoscopes.

It is another object of the present invention to provide an improvedlaryngoscope to incorporate a palate blade fenestration, which allowssome flexion and presents a “target aperture.”

It is another object of the present invention to provide an improvedlaryngoscope to provide an improved angle of the tongue blade.

It is another object of the present invention to provide an improvedlaryngoscope to provide a neck attachment for a penlight illuminationsource.

It is another object of the present invention to provide an improvedlaryngoscope with three different sizes—small, medium, or large.

It is another object of the present invention to provide an improvedlaryngoscope that allows overlap or displacement of the mass of thetongue from the sight line in the center of the mouth.

It is another object of the present invention to provide an improvedlaryngoscope that reduces trauma and potential mechanical failure byputting less force on the blade.

It is another object of the present invention to provide an improvedlaryngoscope in which attachment and removal of the light source isconsiderably easier than the prior art.

It is another object of the present invention to provide an improvedlaryngoscope by providing superior retraction due to its shape.

It is another object of the present invention to provide an improvedlaryngoscope that allows retraction and wider opening of the mouth andairway.

It is another object of the present invention to provide an improvedlaryngoscope with a shortened blade that keeps the invention off thepatient's teeth and not conducive to tissue injury.

It is another object of the present invention to provide an improvedlaryngoscope that provides an unobstructed view of the vocal cordsduring intubation.

It is another object of the present invention to provide an improvedlaryngoscope that allows removal of the laryngoscope over theendotracheal tube without displacing it.

In satisfaction of these and related object, the present invention is aself-retaining laryngoscope, which is an improvement over every knownprior device or method that addresses the problem of establishing andmaintaining the airway, especially in trauma situations

An improved laryngoscope of the present invention affords hands-freeapplication, which is necessary to allow simultaneous suction andintubation. This is especially important in trauma situations. Theimproved laryngoscope also has an improved and broader illumination.

The benefits provided by embodiments of the improved laryngoscope of thepresent invention are a revolutionary laryngoscope that is strong,reliable, inexpensive, and simple to use, while facilitating intubationmore readily and safer than any pre-existing laryngoscope.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the side view of the closed position of the preferredembodiment of the present invention.

FIG. 2 illustrates the side view of the open or retaining position ofthe preferred embodiment of the present invention.

FIG. 3 illustrates the tongue blade component of the preferredembodiment of the present invention.

FIG. 4A shows the palate blade in a closed position on the slider withportions cut away.

FIG. 4B illustrates the palate blade component of the preferredembodiment of the present invention.

FIG. 5A illustrates the slider component of the preferred embodiment ofthe present invention.

FIG. 5B shows the slider with the palate blade in an open position withthe ratchet engaged and a portion of the tongue blade.

FIG. 6 shows a perspective view of the tongue blade.

FIG. 7 shows perspective views of each of the tongue blade, the sliderand palate blade.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, which illustrates the closed position of thepreferred embodiment of the present invention, the self-retaininglaryngoscope is composed of three components: 1) the palate brace orblade 10, 2) the slider 20, and 3) the tongue blade 30.

The tongue blade 30 includes the angulated blade 39 with lightconduction “rail” 32, the light source clip 34, an interface 38, and theteeth 36 for interaction with the slider thumb piece 52 to allowretraction and wider opening of the mouth and airway.

The configuration of the tongue blade 30 has been shown during clinicaltrials to require an angulation 39 of the blade. A straight blade doesnot conform to the natural curve of the airway. The new angle 39 of thepresent invention in its preferred embodiment was clinically tested foroptimization, and was found to be a curve of approximately 60 degrees.It is sized to be either small, medium, or large.

The narrowing of the width of the tongue blade 30 to 2 centimeters is animprovement over the prior art—including the '591 Minson patent—as itallows less material to be used and allows overlap or displacement ofthe mass of the tongue from the sight line in the center of the mouth.It also puts less force on the blade 10, reducing trauma, and potentialmechanical failure. The light conduction rail or light disseminationplatform 32 on the inferior aspect of the tongue blade 30 improvesillumination as well.

Also, and specifically with respect to the '591 Minson patent vis-à-visthe present invention, the tongue blade of the '591 patent was widerthan the width of the tongue. The '591 patent failed as it was thin andcould not support the stress of displacing the mass of the tonguewithout bending or fracturing. It also failed in the retraction of thetongue.

The light source clip 34 on the tongue blade 30 is unique in that it isnot a box configuration such that attachment and removal of the lightsource is considerably easier.

When looking at the tongue blade 30 “end on,” the shape is similar to aninverted pyramid. This represents a far superior alteration orconfiguration as it allows superior retraction due to its shape.

Referring to FIG. 2, which illustrates the open or retaining position ofthe preferred embodiment of the present invention, shows the position ofthe slider 20 when fully engaged, and the palate brace or blade 10 whenfully engaged.

Referring to FIG. 3, which illustrates the tongue blade 30 of thepreferred embodiment of the present invention, the tongue blade 30includes the angulated 39 blade with light conduction “rail” 32, thelight source clip 34, and the teeth 36 for interaction with the sliderthumb piece 52 to allow retraction and wider opening of the mouth andairway.

The angle 39 of the curved tongue blade 30 from the vertical plane ofthe tongue blade 30 piece is critically important and anotherdistinguishing characteristic vis-à-vis the prior art. The optimal angleis 30 degrees from the vertical. Flat blades of prior art do not producethe retraction necessary to facilitate the necessary visualization ofthe vocal cords.

Also, the distal end, which is the farthest insertion into the laryngealvault, of the tongue blade 30 is rounded. This roundness at the distalend minimizes soft tissue trauma. The tapering of the tongue blade 30 atthe most distal end also effectively improved visualization of the vocalcords.

Specifically, based on clinical trials, the optimum width of the tongueblade 30 is one centimeter in width, which proved optimal for retractionand allowed redundant tissue to be retracted in the “locked”configuration. It also allowed the inverted pyramidal shape of thetongue blade 30 to support more force with less material, and thusallowing more operating space in the oropharynx. The length of the blade30 would be determined by the size of the patient, which, according tothe results of the study and is the preferred embodiment, is a 20:2 or10:1 length-to-breadth ratio. The reduction of the width of the blade ofthe present invention represents a critical component and adistinguishing characteristic from the prior art. The wider blades ofthe prior art, including the '591 patent, engaged the force of thetongue in a greater area of surface interaction and attempted to retractcomprehensively across the entirety of the tongue. This can and usuallycreates a critical stress and even mechanical failure of some of theprior art. The narrow width of the preferred embodiment of the presentinvention allows a retraction of the tongue and soft tissue withoutbeing stressed to a breaking point.

Referring to FIG. 4, which illustrates the palate brace or blade 10 ofthe preferred embodiment of the present invention, the structure of thepalate brace or blade 10 is unique. In some prior art, the palate bladeis flat, which would injure tissue and would not retract adequately.Some prior art palate blades, which also levered on the soft palate andcould have injured the tissue, were made of single solid pieces, whichwould effectively block visualization. The palate steps 42(configuration have been built up with “blocks”) in the shortened bladeof the preferred embodiment leverage against the hard palate and keepthe device off the patient's teeth and prevents soft tissue injury.

Furthermore, the palate brace or blade 10 provides the leveragingcapability against the bony palate. The lateral aspect of the palatebrace or blade 10 has been built up or thickened in order to sustaingreater stress and force, and thereby reducing the potential formechanical failure. The palate brace or blade 10 is composed of afenestrated blade that conforms via the “steps” 42 to the palate and thefenestration 48 that provides an unobstructed view of the vocal cordsduring intubation. The configuration of the palate steps 42 in theshortened blade effectively keeps the device off of the patient's teeth.The fenestration 48 of the palate brace or blade 10, which is wider thanan “8” endotracheal tube, allows visualization of the vocal cords duringintubation, and also allows removal of the laryngoscope over theendotracheal tube without displacing it. This is a substantialimprovement over prior art.

The pegs 49 articulate with the peg apertures 50 on the slider 20 andthe ratchet 54 articulates through palate blade aperture 70 with theretaining capacity of the ratchet on the slider 20. The struts 40 on thepalate brace or blade 10 have improved the strength of the mechanism tobear more stress, which reduces the risk of mechanical failure. Inaddition, the lateral aspect of the palate brace or blade 10 has beenbuilt up to further sustain greater stress and force, which furthermorereduces the potential for mechanical failure.

Referring to FIG. 5, which illustrates the slider 20 of the preferredembodiment of the present invention, the slider 20 has three interactiveapplications. The first is the thumb piece 52, which interacts with thetongue blade 30 widening the opening of the mouth, and acts as a biteblock. The second is the ratchet 54, which interfaces with the palateblade aperture 70 to “open” the airway. The third is the pin aperture50, which allows the palate blade 10 to rotate and interact with thetongue blade 30. The slider 20 has been improved over prior art. Theratchet 54 may bear coarser teeth 36 or a slot and groove mechanism toassure the retraction. The struts 40 on the upper rear area of thepalate brace or blade 10 have improved the strength of the mechanism soit can bear more stress, which reduces the risk of mechanical failure.

Although the invention has been described with reference to specificembodiments, this description is not meant to be construed in a limitedsense. Various modifications of the disclosed embodiments, as well asalternative embodiments of the inventions will become apparent topersons skilled in the art upon the reference to the description of theinvention. It is, therefore, contemplated that the appended claims willcover such modifications that fall within the scope of the invention.

1. A laryngoscope having a tongue member and a palate blade memberinterconnected by a slider member that is adjustably attached to aportion of the tongue member and is pivotally connected at a bottom endto a middle portion of the palate blade member; the tongue memberincluding a vertical body portion having front and rear sides, a tongueblade extending in a distal direction from the front side adjacent abottom of the vertical body, the tongue blade having a length to widthratio of about 10:1 and a cross-sectional shape substantially in theform of an inverted pyramid, said tongue blade being positioned at anacute angle relative to the vertical body portion, the vertical bodyportion further including a clip member on the front side and a set ofhorizontal grooves on an upper portion of the rear side; the palateblade member having a rear portion and a front portion, the rear portionhaving a upper section, and a lower section formed with a of spacedapart depending arms, the front portion comprised of two legs thatextend from a bottom portion of the spaced apart depending arms,respectively, the two legs being spaced apart to define an openfenestration there between, a distal end of each of the two legsincluding a depending step and block configuration; the slider memberincluding an upper portion having a latch member that will releasablyinteract with the horizontal grooves on the vertical body, a centrallylocated, rearwardly extending ratchet that will releasably interact withan aperture provided in the upper section of the palate blade to providehands free adjusting of the relative position between the palate bladeand the tongue member.
 2. The laryngoscope as in claim 1 wherein thetongue blade has a width of about 2 centimeters.
 3. The laryngoscope asin claim 1 wherein the tongue blade provides a light conduction path. 4.The laryngoscope as in claim 1 wherein the acute angle is about 60°. 5.The laryngoscope as in claim 4 wherein acute angle ranges from about 30°to about 60°.
 6. The laryngoscope as in claim 1 wherein the dependingstep and block formation includes a downwardly extending step designedto interfit behind teeth in a mouth and the step interacts against apalate portion of a mouth.
 7. The laryngoscope as in claim 1 wherein alateral aspect of each of the two legs is provided with reinforcing topermit the legs to sustain stress associated with opening thelaryngoscope and to position the tongue to provide an open channel tothe larynx.
 8. The laryngoscope as in claim 1 wherein a cup structure isprovided below the clip and adjacent a proximal portion of the tongueblade at the connection with the vertical body portion.
 9. Thelaryngoscope as in claim 1 wherein a distal end of the tongue blade isrounded and tapered.
 10. The laryngoscope as in claim 1 wherein thetongue member has a width of about 1 centimeter.
 11. The laryngoscope asin claim 1 wherein the length of each of the two arms is less than thelength of the tongue blade.
 12. A laryngoscope comprising: a tongueblade member having a proximal tongue blade extending from a distal bodyportion at an acute angle; a palate blade member having a proximalhandle segment, a distal palate blade segment, and a palate blade pivotpoint residing there between; and a support member adjustably attachedto the distal body portion and pivotally connected to said palate blademember at said palate blade pivot point; said distal palate bladesegment comprising two spaced apart arm members having an openfenestration there between; and said proximal handle segment beingoperatively connectable with a ratchet member provided on the supportmember to releasably hold a relative position established between thetongue blade member and a pivoted condition of the palate blade member.13. The laryngoscope as in claim 12 wherein the tongue blade has a widthof ranging from about 1 centimeter to about 2 centimeters.
 14. Thelaryngoscope as in claim 12 wherein the tongue blade provides a lightconduction path.
 15. The laryngoscope as in claim 12 wherein the acuteangle is about 60° relative to an axis of the distal body portion. 16.The laryngoscope as in claim 12 wherein acute angle ranges from about30° to about 60°.
 17. The laryngoscope as in claim 12 further includinga depending step and block formation at a distal end of the two spacedapart arm members which includes a downwardly extending step designed tointerfit behind teeth in a mouth and the step interacts against a palateportion of a mouth.
 18. The laryngoscope as in claim 12 wherein alateral aspect of each of the two spaced apart arm members is providedwith reinforcing to permit each of the two spaced apart arm members tosustain stress associated with opening the laryngoscope and to positionthe tongue to provide an open channel to the larynx.
 19. Thelaryngoscope as in claim 12 wherein a clip is provided on the distalbody portion and a cup structure is provided there below and adjacent aproximal portion of the tongue blade at the connection with the distalbody portion.
 20. The laryngoscope as in claim 12 wherein a distal endof the tongue blade is rounded and tapered.
 21. The laryngoscope as inclaim 12 wherein the tongue member has a length to width ratio of about10:1.
 22. The laryngoscope as in claim 12 wherein the tongue blade has across-sectional shape substantially in the form of an inverted pyramid.